<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>伪类选择器UI伪类</title>
  <style>
    /* 选择的是勾选的复选框或单选框按钮 */
    input:checked{
      width: 100px;
      height: 100px;
    }
    /* 选择的是勾选框禁用 */
    input:disabled{
      background-color: gray;
    }
    /* 选择的是勾选框没有禁用 */
    input{
      background-color: blue;
    }

  </style>
</head>
<body>
  <div>
    <input type="checkbox">
    <input type="radio" name="sex">男
    <input type="radio" name="sex">女
    <input type="text" disabled>
    <input type="text">
  </div>
  
</body>
</html>